DE2113296A1 - New ring-shaped silicon compounds containing hydroxyl groups - Google Patents

Description

FARBENFABRIKEN BAYER AG LEVERKU SEN-Bey.iw.rk

Br-har March 18, 1971

New ring-shaped silicon compounds containing hydroxyl groups

The present compound relates to new ring-shaped hydroxyl group-containing silicon compounds of the general formula

R JCH ₂ OH
C.

(I)

in the

R is hydrogen, an alkyl radical with 1-6 carbon atoms, such as. B. methyl, ethyl, n-propyl, iso-propyl,

η-butyl, iso-butyl, a cycloalkyl radical, such as. B.

Cyclohexyl, an aryl radical, such as. B. phenyl or denotes a methoxymethyl radical, and

R ₁ and R _{2 are} identical or different alkyl radicals, such as

z. B. methyl, ethyl, propyl, butyl or cyclo

alkyl radicals.

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Examples of the connection lengths given above are:

2,2,5-trimethyl-5-hydroxymethyl- (1,3-dioxa-2-sila-cyclohexane), 2, 2-dimethyl-5-ethyl-5-hydroxymethyl- (1,3-dioxa-2-sila-cyclohexane),

2,2-dimethyl-5-butyl-5-hydroxyπlethyl- (1,3-dioxa-2-silaeyclohexane),

2,5-dimethyl-2-ethyl-5-hydroxymethyl- (1,3-dioxa-2-silacyclohexane),

2,2,5-triethyl-5-hydroxymethyl- (1,3-dioxa-2-sila-cyclohexane), 2,2-di-n-butyl-5-ethyl-5-hydroxymethyl- (1,3-dioxa-2-silacyclohexane).

The new Si-terms of the general formula (l) can z. B. duroh the following reactions are obtained;

a) By reacting 1,1,1-tris (hydroxymethyl) alkanes with Dihalodialkylsilanes, such as. B. dichlorodimethylsilane, dichlorodiethylsilane, dichloromethylethylsilane, dichlorodibutylsilane in the presence of tert. Amines such as B. triethylamine or pyridine

HIGH _2x CH ₂ -OH X ^ R _{1 tert} . _Amine

C + Si ^ ^. 1 + 2 tert.

BT CH ₂ -OH T ^ ^X R ₂ ^amine * ^HX

(X = Cl, Br, J)

R, R,, R ₂ have the same meanings as in formula 1

The presence of tert. Amines is not absolutely necessary; When working in solvents or diluents that do not dissolve any significant amounts of hydrogen halides, the addition of the hydrogen halide scavengers remain under.

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b) The compounds of the formula (i) can also be reacted of l, l, l-tris (hydroxymethyl) alkanes with dialkyl

dialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, dibutyldiethoxysilane are produced with the elimination of alcohols:

HIGH ₂ 1IH ₂ OH YO _x / R ^

C + Si> 1 + 2 YOH

IT CH ₉ OH Y0 ^{/ X} R ₉

(Y = e.g. CH, -, C ₉ H ₅ -,

c) Another way of representing (I) is to use the 1,1, i-tris (hydroxymethyl) alkanes with cyclic Alkylsilazanes, such as. B. hexamethylcyclotrisilazane or To bring octamethylcyclotetrasilazane to the reaction with elimination of ammonia:

HIGH ₂ . CH ₂ OH

ⁿ ' + (-SiR ₂ -NH) _n > I + η NH ₃

² ° ^H (n = 3, 4)

As 1,1, i-tris (hydroxymethyl) alkanes, for. B. the cheap compounds 1,1,1 —tris (hydroxymethyl) methane, -ethane, -propane or -hexane are used.

The reaction is generally carried out in accordance with the reactions a) in the presence of a solvent. For this purpose, those that are against all participants in the reaction are primarily suitable are inert such as B. benzene, toluene, petroleum ether or xylene.

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The presence of a solvent is not necessary in the reaction according to b) and c). But here too, like "at a) worked in inert solvents or diluents will. In the reaction according to b) it is advisable to use substances that accelerate the splitting off of alcohol, such as e.g. to add p-toluenesulfonic acid in small amounts.

In general, the reaction mixture is heated in all reactions. It is advisable to work at temperatures between about 25 and 20O ⁰ C, but in certain cases this temperature range can also be exceeded or fallen below.

The reactions preferably take place under normal pressure. Diminished however, or elevated pressures (from about 0.1 atm. to about 5 atm.) can also be used.

The reaction products are generally worked up by distillation methods. The new compounds represent liquids. When standing at room temperature occurs slow polymerization, which is noticeable by an increase in the relative viscosity. By distillation the substances can be depolymerized again.

The compounds according to the invention are very suitable as aids for mold removal in the molding of plastic or rubber articlesQ, as well as'for the aftertreatment of pigments.

The compounds according to the invention and their preparation are to be explained in more detail with the aid of the following examples.

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example 1

Production of 2,2-dimethyl-5-ethyl-5-hydroxymethyl- (1,3-dioxa-2-sila-cyclohexane)

2010 g 1,1,1-trimethylolpropane and 1000 ml benzene were on Heated to 70 ° and stirred well. At this temperature 1935 g of dimethyldichlorosilane were slowly added dropwise, simultaneously HCl escaped. After the dimethyldichlorosilane had been added dropwise, the mixture was heated under reflux conditions until until no more HCl escaped. The reaction mixture was then freed from benzene and distilled.

Yield: 2440 g of ^K Po, 65 ⁸⁹ ° ⁿ D ° ¹ » ⁴⁵⁰⁴ Analysis: CgH _1Q 0 ^ Si

Ber. C 50.5 % " H 9.47 % Si 14.75 %

Found 50.3 9.65 14.30

Example 2

In an analogous manner, starting from 1,1,1 -trimethylolethane, 2,2, S-trimethyl-S-hydroxymethyl- (1,3-dioxa-2-sila-cyclohexane) bp _{0 6} 70 ° C n | ° 1, 4512 manufactured. -

Analysis: C, ₇ H _{i 6} O ₃ Si 9, 08 % Si 15, 90 Ber. C. 47 , 7 % H. 9, 14th 16, 30th Found 48 , ι example 3

134 g of 1,1,1-tris-hydroxymethyl propane (1 mol) and 148 g of diethoxydimethylsilane (1 mol) were heated to 90-100 ° C. with 0.05 g of p-toluenesulfonic acid. At the same time, 2 mol of ethanol distilled off. The reaction product was distilled. 157 g of 2,2-dimethyl-5-ethyl-5-hydroxymethyl- (1 ^ -dioxa ^ -sila-cyclohexane) were obtained. Kp _1j0 92 ° C n§ ° 1.4515

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Example 4

3350 g of 1, igl-tri-hydroxymethy! Propane (25 mol) was on Heated to 120 ° C. »Then 2117 g of hexamethylcyclotrisilazane were added added dropwise “At the same time, 424 g = 25 mol of ammonia were released.

The reaction product was distilled. There were 4380 g 2.2-0 ^ 6 ^ 71-5 ^^ 1-5-3 ^^: ^ 1 ^ 1171 »(1,3-dioxa-2-silacirclohexane) obtain.

Kp ₀ ^ ₅ 88 ° C n | ° 1.4520

Example 5

402 g 1J1 _f 1-tri-hydroxymethyl propane and 606 g of triethylamine and 1000 ml of benzene! Were heated to 40 ° C and stirred well. At this temperature, 387 g of dimethyldichlorosilane were added dropwise and the mixture was then stirred for 2 hours. The precipitated triethylammonium hydrochloride was filtered off. 480 g of 2,2-diethyl-5-ethyl-5-hydroxymethyl- (1,3-dioxa-2-sila-cyclohexane) could be isolated from the filtrate by distillation »

⁹⁰ ° ^{C n2} D ¹ ' ⁴⁵²³
Example 6

176 g of 1,1,1-frishydroxymethylheptane (1 mol) were heated to 120 ° heated and 75 g of hexamethylcyclotrisilazane were added dropwise. Included 17 g of ammonia were released.

The Uiasetsiimga product was fralrt. distilled. It could 155.1 g of 2,2 "-dimethyl-5- = n- = p © ntyl '> = 5-hydroxyniethyl- (1,5-dioxa-

2-sila-cyclohexane) ·, Ep _{Q 5} 1O3 °, n ^ ° 1.4548 can be isolated.

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Analysis: ^c i2 ^H 24 ^Si0 2

Ber. C 56.8 H 10.35 Si 12.07 Found 56.6 10.6 12.30

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Claims (3)

Patent claims: (^ JL ^ / Ring-shaped silicon compounds containing hydroxyl groups the general formula R XJH ₂ OH where R = hydrogen, an alkyl radical with 1-6 carbon atoms, a substituted or unsubstituted cycloalkyl radical or an aryl radical, R ₁ and Rp »identical or different alkyl or substituted or unsubstituted cycloalkyl radicals 2) Process for the preparation of the compounds according to claim 1, characterized in that l.l.l.-tris (hydroxymethyl) alkanes with dihalodialkylsilanes in the presence of tert. Amines are implemented. 3) Process for the preparation of the compounds according to claim 1, characterized in that III-tris (hydroxymethyl) alkanes are reacted with dihalodialkylsilanes or with dialkyldialkoxysilanes or with cyclic alkylsilazanes . Le A 13 592 - 8 - 209839/1194